LS3 conversion

Hi all,

I’ve been working on this project since April and am just finishing up.

I’ve got a couple question regarding the cluster that I was hoping someone could help me out with:

I’ve started the car successfully and am getting no codes when diagnosing the GM computer ( I’ve also tied the MIL into the cluster) but the red idiot light is illuminated as is the engine oil level light (the one with the dipstick). I’m assuming that the two lights are tied together... if that is the case, how do I deactivate the oil level light?

I’ve read that one solution is to ground the yellow/white wire on the cluster.. is this the approach? I wanted to double check before I started cutting wires.

I’ll post pictures of the project soon via this thread. Thanks for any help

Car pic from the ad
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Engine bay (previous own was going to swap in a 1.8 after the engine fire)
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Body delivered and cleaned up!
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Crate LS3
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Oil Pressure Sender & adapter
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Flywheel Installed
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Accessories Installed (CTS-V FEAD)
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TPC Manifolds
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Dropped the Transaxle
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only944 Short Shift kit installed (Put new seals in too)
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HydroBoost installed
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Fuel Tank dropped to be cleaned
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Engine about to be hoisted
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Engine up
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Crossmember spacers
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Coil packs moved
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Computer Mounted on stock bracket
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Fuse box in Battery tray
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Junction/Battery master switch
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Remote Battery Cable routing
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Radiator and Fans
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Rad Bracket 3D Model and part installed
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Fuel Pump & filter
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Clutch& Pressure Plate Installed
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Rotors Before, Beadblasted, Painted/Surfaced
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Stainless Brake lines
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Intake Mockup
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All done!
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Apologies for the huge post....

Very clean build! Locate the oil level sender plug on the stock 944 harness and ground it to the chassis. That will turn the light off.

Looks great, nice job!! I have the same LS3 on the engine stand as we speak.
The low oil level sensor is just a switch so grounding should work.
Any hood clearance with the CTS-V accessories? Did the A/C compressor hit the frame rail?

Thank you!

I ended up grounding the wire from the cluster and it turned out the light, but I still have the (!) light illuminated along with the airbag and seatbelt light. I'm thinking they are connected somehow, and am hoping the airbag reset procedure turns them all off...
Can anyone confirm this? TIA

Also the CTS-V Fead kit fits really well. The only thing that is close in terms of hood clearance is the Power Steering Reservoir, which I egged the mounting holes so it sits lower, you can easy mount the reservoir elsewhere though. I liked the stock look.

I don't have the AC lines hooked up to the compressor yet... but the clearance doesn't seem to be an issue. The issue I'm having is finding fittings/AC manifold for the CTSV compressor, since most swaps/aftermarket utilize the F Body compressor and bracket (has a different AC manifold).

If anyone has info on that I'd be happy to hear it as well!

tannerhwilson wrote:Thank you!

I ended up grounding the wire from the cluster and it turned out the light, but I still have the (!) light illuminated along with the airbag and seatbelt light. I'm thinking they are connected somehow, and am hoping the airbag reset procedure turns them all off...
Can anyone confirm this? TIA

Also the CTS-V Fead kit fits really well. The only thing that is close in terms of hood clearance is the Power Steering Reservoir, which I egged the mounting holes so it sits lower, you can easy mount the reservoir elsewhere though. I liked the stock look.

I don't have the AC lines hooked up to the compressor yet... but the clearance doesn't seem to be an issue. The issue I'm having is finding fittings/AC manifold for the CTSV compressor, since most swaps/aftermarket utilize the F Body compressor and bracket (has a different AC manifold).

If anyone has info on that I'd be happy to hear it as well!

Any warning light on in the cluster will trigger the (i). Once you reset the airbag and connect your seat belt buckle, the (i) should go off.

As far as A/C fittings, I get a lot of them from this place. [You must be registered and logged in to see this link.]
You can also check to see if there is an automotive A/C shop in your area. They can usually get what you need as well. On a lot of the LS swaps that I do, I use the aftermarket compressor and mount. It's much easier to find fittings for them, and they usually sit a little closer to the engine.

Were you able to use the crank pulley and water pump that came with the crate LS3?

All I have left to buy is the front accessory drive system.. I have been worried I'll get the wrong kit. Again your install is very nice.. following the body lines with all of the wiring and hoses is the right way to do it. I've built a fer cars in my day and that attention to detail is what really make a difference..

I noticed in your pictures that you have the fuel regulator in the back. I have read many places that this is normally put up at the engine to keep full fuel pressure. There are many write ups about this, but I am not the expert. I just wanted to point it out so you do not have a problem when you were working out any issues that come up.

there is actually mixed info on this. the old school method for efi was a return system with the regulator in the front, plumbed after the fuel rail. newer cars (like the ls stuff) run a dead head fuel system with the regulator in the back. some ls cars have the regulator built in the fuel tank, others have it in the fuel filter.

whats best? really depends on the whole fuel system design. last year my shop finished off our mazda r100 with a 1000hp 3 rotor that runs e85, and we are running the regulator in the back and deadheading the fuel rails. we also have pulse dampers on the rails to take some of the pressure fluctuations out. we have had no issues whatsoever with the fuel system.

Thanks for the info and recommendations, I performed the airbag reset as per Clarks... all the lights went out but then reilluminated shortly after... Guess I have some underlying issues that I'll have to sort out. Looking into the AC lines now.

As far as the pulleys and pump, yes I used everything that came on the engine, no switching involved. Only adjustment I made was that I pulled the power steering pulley out a tad to clear the AN adaptor for the hydroboost line (like 1/16 in). I'm really happy with how the wiring and plumbing came out, means a lot to have that planning aspect noticed as it's my first swap attempt ever.

As far as the fuel filter/regulator, the kit I got from TPC locates it in the stock location. So far it hasn't caused any issues.

My back tires are rubbing when the car squats down under acceleration. Thinking I need to roll the fenders and address the torsion bar. Either adjust the ride height up, look into stiffening the rear end via a new bar, or coilovers. I've seen a bunch of different options but don't know the benefits of each route.. This is a street car that may very rarely see the track.

depending on the your alignment, you may be able to just add a little camber to get the clearance.

going with stiffer torsion bars will be the cheapest option, however its the most work. i bought a set of bars california imports, they were around $200 for the pair. the problem is you gotta tear the entire rear suspension out to change them. its not the worst idea though, if original, all the rubber bushings will be soft and its a great time to change them out.

coilovers in the back are alother good option, but there are things to consider. with a coil over you can either go with a soft spring and essentially use it as a "helper spring" to work with the torsion bars. essentially what you do is crank the ride height adjusters to the lowest setting and adjust the ride height with the coilovers. the other method is to use a stiff spring and remove the torsion bars, this gives better adjustability and you also lose the weight of the torsion bars. the downside here is it puts all the stresses on the shock mount bolt and the trailing arm where they werent designed for such load. you also need to change the spring plate bushings to the poly bronze ones as the coilover causes the rubber bushings to deflect quite bad.

i ended up doing stiffer torsion bars in my car this past winter as the coilovers were out the budget at the time. im actually quite pleased with the way the car works. it was a lot of work to change them, and i did change every rubber bushings to solid and spherical joints. it was likely overkill for what im doing with the car, im sure delrin or poly would have been just fine.

Fixed the rubbing by rolling them, but now I’ve encountered another problem... a bit more serious...

Noticed that the car was acting a bit strange the last week... after applying throttle there is a brief pause and then a thunk that I can hear and feel. Same happens when going off throttle.

On the way home it was getting worse and worse, so I was trying to baby it. Car broke down the first street in my town. Transmission is no longer engaged, and there’s an awful sound when letting go of the clutch. Thinking either the driveshaft broke or the clutch hub totally separated.

Will be dropping the inspection plate soon, but does anyone have any insight? Has anyone ever heard of this?

Thanks

i think the best thing to do is unhook the driveshaft coupler at the transmission and see what turns. if you can turn the driveshaft you have something wrong with the clutch. with the trans in gear, if you can turn the input shaft without the axles turning you have something failed in the trans.

It does sound like a problem with the clutch disc or drive shaft. Were you able to measure depth of insertion of the drive shaft tip in the pilot bearing? Pulling the lower cover of the bell housing and releasing the coupler to the trans are good steps to see what happened.

There are always teething pains with these builds. Hope this one's is not too bad.

Hope it's not ring/pinion gear. You could remove the lower drain plug and check for metal chunks or shavings. Stick a wire with a hook on it, in there and drag the floor of the trans axle case

Good luck..

Dropped the bh cover...

Had a buddy sit in the car and press the clutch pedal in and used a screwdriver to push the clutch to check any play. Sure enough there was play when I pressed the disk up, and the entire clutch hub could be independently turned radially from the drive shaft. Either the hub splines failed or the driveshaft splines failed... hoping it’s the clutch... maybe it was cheap or hadn’t been properly treated...

Also put the trans in neutral and was able to rotate the driveshaft, but could not rotate the driveshaft when in gear, so the trans is fine.

I’ll be dropping it anyway to get a better look at the clutch and to have the synchros rebuilt. Is the aor box worth it?

Well, good news on the trans... And yes, the AOR is the one to have.

What clutch disc was it? I used SPEC and had good luck but others have had trouble.

the aor is the best trans to have, although the few upgraded pieces they have over a regular turbo box are not too likely to be the cause of a failure. the aor has few parts (1st and 2nd gear, diff shafts) that have been shot peened to reduce stress point on them, making them stronger. they also do have different internals in the limited slip than the other 944 limited slip diffs. the parts that have been shot peened are rarely the parts you see fail in a normal turbo box, most of the time its a ring and pinion failure.

imo if you have a turbo box with a limited slip that just needs syncros, you may as well have that rebuilt instead of buying an aor. keep in mind the aor is an expensive transmission because they are rare. i bought one for my swap, but knowing what i do now i likely wouldnt have spent the extra on it over another version.

It was the TPC conversion clutch (Chrysler/dodge disk). Leaning towards getting the spec stage 1 or 2 disk as a replacement if it is indeed the clutch. As for the trans I have a UY (turbo no LSD, no cooler). Should I just go for an aor when the trans blows? Or add an aftermarket LSD to my trans?

Thanks for the info! Will report back when I confirm what the problem is.

Street car? You probably don't need the cooler. I ran a 5P non-turbo, no cooler for my first track season after the conversion. I babied it in 1st and 2nd gears as a rule and it was fine, but the fluid that came out after was cooked. I then got an AOR and the diff makes a huge difference on track. And after 2 seasons the fluid that came out still looked good. YMMV

Rich

Took the transaxle out and was able to move back the driveshaft/torque tube assembly enough to get a look at the driveshaft... splines are rounded... very disgusted to say the least...

Dang, that's ugly. Need a replacement torque tube I'd say. Good news is the 944 is plentiful in wrecker yards. Any old 944 will do, right? And yeah, maybe go SPEC disc this time. I'm running the stage 2 and it's totally street-able.

Rich

Here's some picture of the clutch splines, strange it only ground half of the shaft:
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Heres the view from the other side:
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Double checked the pilot bearing and its engagement too:
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Looked all good...

I'm figuring that the front torque tube bearing (or multiple) failed... when turning the driveshaft I could hear and feel some drag. Pulled down on the driveshaft and it had some play... I could move it down a considerable amount. I think that the tiny bit of play with the chrysler clutch disk splines probably didn't help either.